Balanced forces ppt
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This document discusses levers and moments. It provides examples of levers in the body, such as bones and joints. It explains that the longer the lever, the bigger the force needed to move an object. It also discusses moments and how they are calculated by multiplying force by distance from the pivot. Examples are provided about balancing moments on a seesaw. The document also discusses how counterweights on cranes allow them to lift heavy loads by balancing the moments of the load and counterweight.
Balanced forces ppt
- 2. Levers
- 3. Write out the statements that are true. • a The longer the lever, the bigger the force that is needed to move an object. • b It is easier to close a door if you push the door close to the hinge • c The shorter the lever, the bigger the force that is needed to move an object • d Joints are examples of pivots. • e Bones are examples of levers.
- 4. C, D and E
- 5. Learning Objective To investigate, through practical experimentation, the principle of moments.
- 7. • What do we need to record? • How many columns will we need in our table? Recording your results
- 10. Weight and Mass • YouTube - Eureka! Episode 7 - Weight vs. Mass YouTube - Eureka! Episode 6 - Gravity Racing Balls
- 11. Write out each term along with its correct description Descriptions • anticlockwise moments = clockwise moments • two boys of different weights sit opposite each other on a see saw, both the same distance from the pivot • the turning effect of a force moment balancedsystem unbalanced system Lever Principle GCSE PHYSICS: Moments
- 12. Gina weighs 500N and stands on one end of a seesaw. She is 0.5m from the pivot. What moment does she exert? moment = 500 x 0.5 = 250 Nm 0.5m 500N pivot Moment calculation
- 13. moment = force (N) x distance from pivot (cm or m) The moment of a force is given by the equation: Moments are measured in Newton centimetres (Ncm) or Newton metres (Nm). moment f x d Moment equation
- 14. Principle of moments The girl on the right exerts a clockwise moment, which equals... The girl on the left exerts an anti-clockwise moment, which equals... her weight x her distance from pivot her weight x her distance from pivot
- 15. Principle of moments When something is balanced about a pivot: total clockwise moment = total anticlockwise moment If the anticlockwise moment and clockwise moment are equal then the see-saw is balanced. This is known as the principle of moments.
- 16. Two girls are sitting on opposite sides of on a see-saw. One girl weighs 200N and is 1.5m from the pivot. Where must her 150N friend sit if the seesaw is to balance? When the see-saw is balanced: Principle of moments – calculation total clockwise moment = total anticlockwise moment 200N x 1.5m = 150N x distance 200 x 1.5 = distance 150 distance of second girl = 2m
- 17. Anagrams
- 18. Tower cranes are essential at any major construction site. load arm trolley loading platform tower Concrete counterweights are fitted to the crane’s short arm. Why are these needed for lifting heavy loads? counterweight Why don’t cranes fall over?
- 19. Using the principle of moments, when is the crane balanced? moment of = moment of load counterweight If a 10,000N counterweight is three metres from the tower, what weight can be lifted when the loading platform is six metres from the tower? 6m 3m 10,000N? Why don’t cranes fall over?
- 20. moment of counterweight distance of counterweight from tower = = 10,000 x 3 = 30,000 Nm counterweight x moment of load = = ? x 6 load x distance of load from tower moment of load = moment of counterweight ? x 6 = 30,000 ? = 3,000 6 ? = 5,000 N Why don’t cranes fall over?
- 21. Where should the loading platform be on the loading arm to carry each load safely? Crane operator activity